/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xalan.templates;

import javax.xml.transform.TransformerException;

import wx.xml.xalan.xalan.res.XSLTErrorResources;
import wx.xml.xalan.xalan.transformer.TransformerImpl;
import wx.xml.xalan.xpath.XPathContext;
import wx.xml.xalan.xpath.objects.XObject;

/**
 * Implement xsl:choose.
 * <pre>
 * <!ELEMENT xsl:choose (xsl:when+, xsl:otherwise?)>
 * <!ATTLIST xsl:choose %space-att;>
 * </pre>
 *
 * @xsl.usage advanced
 * @see <a href="http://www.w3.org/TR/xslt#section-Conditional-Processing-with-xsl:choose">XXX in XSLT Specification</a>
 */
public class ElemChoose extends ElemTemplateElement {
    static final long serialVersionUID = -3070117361903102033L;

    /**
     * Constructor ElemChoose
     */
    public ElemChoose() {
    }

    /**
     * Get an int constant identifying the type of element.
     *
     * @return The token ID for this element
     * @see wx.xml.xalan.xalan.templates.Constants
     */
    public int getXSLToken() {
        return Constants.ELEMNAME_CHOOSE;
    }

    /**
     * Return the node name.
     *
     * @return The element's name
     */
    public String getNodeName() {
        return Constants.ELEMNAME_CHOOSE_STRING;
    }

    /**
     * Execute the xsl:choose transformation.
     *
     * @param transformer non-null reference to the the current transform-time state.
     * @throws TransformerException
     */
    public void execute(TransformerImpl transformer) throws TransformerException {

        if (transformer.getDebug())
            transformer.getTraceManager().fireTraceEvent(this);

        boolean found = false;

        for (ElemTemplateElement childElem = getFirstChildElem();
             childElem != null; childElem = childElem.getNextSiblingElem()) {
            int type = childElem.getXSLToken();

            if (Constants.ELEMNAME_WHEN == type) {
                found = true;

                ElemWhen when = (ElemWhen) childElem;

                // must be xsl:when
                XPathContext xctxt      = transformer.getXPathContext();
                int          sourceNode = xctxt.getCurrentNode();

                // System.err.println("\""+when.getTest().getPatternString()+"\"");

                // if(when.getTest().getPatternString().equals("COLLECTION/icuser/ictimezone/LITERAL='GMT +13:00 Pacific/Tongatapu'"))
                // 	System.err.println("Found COLLECTION/icuser/ictimezone/LITERAL");

                if (transformer.getDebug()) {
                    XObject test = when.getTest().execute(xctxt, sourceNode, when);

                    if (transformer.getDebug())
                        transformer.getTraceManager().fireSelectedEvent(sourceNode, when,
                            "test", when.getTest(), test);

                    if (test.bool()) {
                        transformer.getTraceManager().fireTraceEvent(when);

                        transformer.executeChildTemplates(when, true);

                        transformer.getTraceManager().fireTraceEndEvent(when);

                        return;
                    }

                } else if (when.getTest().bool(xctxt, sourceNode, when)) {
                    transformer.executeChildTemplates(when, true);

                    return;
                }
            } else if (Constants.ELEMNAME_OTHERWISE == type) {
                found = true;

                if (transformer.getDebug())
                    transformer.getTraceManager().fireTraceEvent(childElem);

                // xsl:otherwise
                transformer.executeChildTemplates(childElem, true);

                if (transformer.getDebug())
                    transformer.getTraceManager().fireTraceEndEvent(childElem);
                return;
            }
        }

        if (!found)
            transformer.getMsgMgr().error(
                this, XSLTErrorResources.ER_CHOOSE_REQUIRES_WHEN);

        if (transformer.getDebug())
            transformer.getTraceManager().fireTraceEndEvent(this);
    }

    /**
     * Add a child to the child list.
     *
     * @param newChild Child to add to this node's child list
     * @return The child that was just added to the child list
     * @throws DOMException
     */
    public ElemTemplateElement appendChild(ElemTemplateElement newChild) {

        int type = ((ElemTemplateElement) newChild).getXSLToken();

        switch (type) {
            case Constants.ELEMNAME_WHEN:
            case Constants.ELEMNAME_OTHERWISE:

                // TODO: Positional checking
                break;
            default:
                error(XSLTErrorResources.ER_CANNOT_ADD,
                    new Object[]{newChild.getNodeName(),
                        this.getNodeName()});  //"Can not add " +((ElemTemplateElement)newChild).m_elemName +

                //" to " + this.m_elemName);
        }

        return super.appendChild(newChild);
    }

    /**
     * Tell if this element can accept variable declarations.
     *
     * @return true if the element can accept and process variable declarations.
     */
    public boolean canAcceptVariables() {
        return false;
    }

}
